Coke oven flue gas back blending feedforward-feedback collaborative control method and system

Abstract

This invention discloses a feedforward-feedback coordinated control method and system for coke oven flue gas recirculation, belonging to the field of coke oven combustion optimization and environmental protection control technology. It addresses the shortcomings of existing technologies, such as lag in recirculation control, poor adaptability to operating conditions, and inability to simultaneously control NO. x To address the issues of emission reduction and heating efficiency, this invention provides a method comprising: real-time acquisition of gas flow rate and flue gas suction, calculating the target recirculation ratio through feedforward to predict changes in operating conditions; simultaneously, real-time acquisition of flue gas oxygen content and actual total flow rate, correcting the feedforward ratio through feedback correction calculation to eliminate deviations; and finally, fusing the feedforward and feedback results to generate a control signal for precise adjustment of the recirculation ratio. The corresponding system includes modules for data acquisition, feedforward calculation, feedback correction, fusion control, and execution. This invention achieves dynamic optimization control of the recirculation ratio, effectively reducing NOx emissions. x It reduces emissions and improves heating efficiency and operational stability.

Description

Technical Field

[0001] This invention belongs to the field of coke oven combustion optimization and environmental control technology. Specifically, this invention relates to a method and system for precise control of coke oven flue gas recirculation based on flue gas flow rate and damper suction feedforward, and flue gas oxygen content and flow rate feedback. It is applicable to coke ovens with thermal NO x Scenarios for synergistic optimization of emission reduction and heating efficiency. Background Technology

[0002] Coke ovens are core equipment in the steel industry, and their combustion process produces thermal NO. x NO is a major air pollutant, and its presence is verified based on the coke oven combustion mechanism and industrial data. x The amount of NO produced is significantly positively correlated with the furnace temperature—when the furnace temperature exceeds 1260℃, NO production increases. x Emissions are increasing exponentially. Flue gas recirculation technology, by mixing some of the post-combustion flue gas with combustion air and re-involving it in combustion, can achieve NO reduction through a triple effect: diluting oxygen concentration, smoothing peak combustion temperature, and enhancing the uniform distribution of heat circulation. x Synergistic benefits of emission reduction and improved heating efficiency.

[0003] However, existing coke oven flue gas recycling and control technologies have the following drawbacks:

[0004] 1. The recirculation rate adjustment often uses fixed ratios or manual adjustments, lacking the ability to dynamically adapt to real-time operating conditions. Fluctuations in coke oven gas flow rate (combustion load) and flue gas suction (which determines air supply when damper opening is fixed) can cause the actual recirculation ratio to deviate from the optimal range. If the ratio is too low, it cannot effectively dilute the oxygen concentration, leading to increased NO content. x Insufficient emission reduction effect; too high a ratio will lead to too low oxygen concentration for combustion, resulting in incomplete combustion of fuel, reduced heating efficiency and increased gas consumption per unit.

[0005] 2. Existing control methods lack a coordinated mechanism of "feedforward prediction and feedback correction": relying solely on feedback adjustment results in significant control lag, making it difficult to cope with sudden changes in operating conditions (such as sudden changes in gas flow rate and suction fluctuations); relying solely on fixed-proportion feedforward cannot correct deviations in actual reflow volume caused by equipment errors and environmental disturbances, leading to NO... x The emission concentration fluctuates greatly, and the heating efficiency is unstable.

[0006] 3. The lack of a closed-loop correlation between the remixing amount and key combustion parameters (such as oxygen content) makes it impossible to reflect combustion completeness in real time through oxygen content, easily leading to problems of "over-dilution" or "under-dilution," and making it difficult to simultaneously address NO levels. x The dual objectives are emission reduction and heating efficiency.

[0007] This paper provides a feedforward-feedback coordinated control method for coke oven flue gas recirculation, specifically addressing how to ensure that the flue gas recirculation ratio is always within the optimal range to achieve NO reduction. x Stable emission reduction, improved heating efficiency and reduced energy consumption. Summary of the Invention

[0008] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a feedforward-feedback coordinated control method for coke oven flue gas recirculation, with the purpose of ensuring that the flue gas recirculation ratio is always within the optimal range, thereby achieving NO reduction. x Stable emission reduction, improved heating efficiency and reduced energy consumption.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is: a feedforward-feedback coordinated control method for coke oven flue gas recirculation, comprising the following steps:

[0010] Real-time acquisition of coke oven operating parameters, including at least coke oven gas flow rate and flue gas suction;

[0011] Based on the coke oven gas flow rate and the flue gas suction, the feedforward target recycle amount is obtained through feedforward calculation.

[0012] Real-time collection of flue gas oxygen content and actual total flue gas flow rate; based on the deviation between the flue gas oxygen content and the target flue gas oxygen content, and the deviation between the actual total flue gas flow rate and the theoretical total flue gas flow rate, the feedback correction amount is calculated through feedback correction.

[0013] The feedforward target reprocessing amount and the feedback correction amount are fused to obtain the final reprocessing amount, and the flue gas reprocessing equipment is controlled according to the final reprocessing amount.

[0014] The feedforward target allocation amount is obtained through feedforward calculation, specifically as follows:

[0015] The theoretical total flue gas volume is calculated based on the coke oven gas flow rate and the suction force of the flue gas duct.

[0016] The feedforward target recycle amount is obtained by multiplying the theoretical total flue gas volume by the preset target recycle ratio.

[0017] The theoretical total flue gas volume V fl Calculated using the following formula:

[0018]

[0019] Where Vg is the coke oven gas flow rate, a is the flue gas suction, and 0.66, 17162, and -118386 are coefficients determined based on the coke oven gas composition and combustion characteristics.

[0020] The target blending ratio is dynamically adjusted according to the coke oven operating conditions; when the coke oven temperature exceeds a preset threshold, the target blending ratio is increased.

[0021] The feedback correction amount is calculated through feedback correction, specifically as follows:

[0022] Calculate the deviation of oxygen content in flue gas, ΔO2. Where O2 is the measured oxygen content in the flue gas, and O 2，s The target is the oxygen content in the flue gas;

[0023] Calculate the total flow deviation ΔV f , V f V represents the actual total flue gas flow rate, and V represents the theoretical total flue gas flow rate.

[0024] The control algorithm is used to perform a fusion calculation on the deviation of the flue gas oxygen content and the deviation of the total flow rate, and the feedback correction amount is output.

[0025] The control algorithm is a proportional-integral-derivative PID algorithm, and the feedback correction quantity V hf Calculated using the following formula:

[0026]

[0027] ΔV f The total flow rate deviation is represented by ΔO2, the flue gas oxygen content deviation is represented by ω1 and ω2, and K is the weighting coefficient. p K i K d Here are the PID parameters, and K1 is the proportional coefficient.

[0028] The present invention also provides a feedforward-feedback coordinated control system for implementing the method of coke oven flue gas recirculation, comprising:

[0029] The data acquisition module is used to collect coke oven operating parameters in real time. The operating parameters include at least coke oven gas flow rate, flue gas suction, flue gas oxygen content, and actual total flue gas flow rate.

[0030] The feedforward calculation module is used to calculate the feedforward target recirculation amount based on the coke oven gas flow rate and the flue gas suction.

[0031] The feedback correction module is used to calculate the feedback correction amount based on the deviation between the oxygen content of the flue gas and the target oxygen content of the flue gas, and the deviation between the actual total flue gas flow rate and the theoretical total flue gas flow rate.

[0032] The fusion control module is used to fuse the feedforward target re-allocation amount with the feedback correction amount to obtain the final re-allocation amount and generate a control signal;

[0033] An execution module is used to adjust the flue gas recirculation amount according to the control signal.

[0034] The data acquisition module includes a gas flow meter, a flue gas pressure sensor, a flue gas oxygen analyzer, a total flue gas flow sensor, a return flow sensor, an infrared thermometer, and a NO meter. x Online monitoring instrument.

[0035] The feedforward calculation module has a built-in theoretical total flue gas calculation model and a target remix ratio setting value;

[0036] The feedback correction module has a built-in PID control algorithm to handle the deviation in flue gas oxygen content and the deviation in total flow rate.

[0037] The execution module is a variable frequency fan, which controls the amount of flue gas recirculation by adjusting the operating frequency.

[0038] The data acquisition module is also used to acquire the coke oven temperature, and the feedforward calculation module dynamically adjusts the target recycle ratio based on the coke oven temperature.

[0039] The feedforward-feedback coordinated control method for coke oven flue gas recirculation of the present invention has the following beneficial effects:

[0040] 1. High control precision: Feedforward regulation is based on calculated flue gas flow rate (theoretical flue gas volume) and damper suction, adapting to changes in operating conditions in advance and avoiding the lag of feedback control; feedback regulation combines oxygen content and actual total flow rate to correct deviations in real time, ensuring that the refluxing ratio remains stable within the optimal range of 18%, NO x Emission concentration can be stably controlled at 350 mg / Nm³ 3 The following emission reduction rates are above 22.2%;

[0041] 2. Significant synergistic benefits: Through closed-loop control of oxygen content and actual total flow rate, insufficient or excessive dilution is avoided, achieving NO... x While reducing emissions, heating efficiency was effectively improved, and the gas consumption per unit area was reduced to 193.79m³. 3 / ton of coke or less, the consumption of denitrification ammonia water per ton of coke is reduced by 1.22 kg, taking into account both environmental protection and economic benefits;

[0042] 3. Strong adaptability to operating conditions: The target blending ratio can be dynamically adjusted according to operating conditions such as furnace temperature and coking time to maximize benefits under all operating conditions.

[0043] 4. Good operational stability: Through feedforward-feedback fusion control, it effectively resists the interference of fluctuations in parameters such as gas flow and flue gas suction, and the temperature of the furnace top space is stabilized at around 820℃. The uniformity of high-altitude heating is significantly improved, and the service life of coke oven equipment is extended. Attached Figure Description

[0044] This manual includes the following figures, which illustrate the following:

[0045] Figure 1 This is a graph showing the relationship between flue gas recycling ratio and NOx formation. Detailed Implementation

[0046] The following description of the embodiments provides a more detailed explanation of the specific implementation of the present invention, with the aim of helping those skilled in the art to have a more complete, accurate, and in-depth understanding of the concept and technical solutions of the present invention, and facilitating its implementation.

[0047] In a first aspect, the present invention provides a feedforward-feedback coordinated control method for coke oven flue gas recirculation, comprising the following steps:

[0048] S1. Real-time acquisition of coke oven operating parameters, including at least coke oven gas flow rate and flue gas suction.

[0049] S2. Based on the coke oven gas flow rate and the suction of the flue, the feedforward target recirculation amount is obtained through feedforward calculation.

[0050] S3. Real-time acquisition of flue gas oxygen content and actual total flue gas flow rate; based on the deviation between flue gas oxygen content and target flue gas oxygen content, and the deviation between actual total flue gas flow rate and theoretical total flue gas flow rate, the feedback correction amount is calculated through feedback correction.

[0051] S4. The feedforward target reprocessing amount and the feedback correction amount are fused to obtain the final reprocessing amount, and the flue gas reprocessing equipment is controlled according to the final reprocessing amount.

[0052] Specifically, in this embodiment of the invention, a feedforward-feedback coordinated control method and system for coke oven flue gas recirculation is provided. Feedforward prediction is achieved through flue gas flow rate and damper suction, while feedback correction is achieved through flue gas oxygen content and recirculation flow rate. This ensures that the recirculation ratio dynamically matches the coke oven operating conditions and remains within the optimal range (around 18%), ultimately achieving NO reduction. x The synergistic goals of emission reduction, improved heating efficiency, and reduced gas consumption per unit area.

[0053] The coke oven flue gas recycling feedforward-feedback coordinated control method provided in this embodiment of the invention is based on the coke oven combustion reaction mechanism, the law of conservation of materials, and industrial operating condition optimization data. It adapts to the operating conditions in advance through feedforward adjustment and corrects deviations in real time through feedback adjustment.

[0054] In step S1 above, operating parameters are acquired in real time. Key operating parameters of the coke oven are acquired in real time through a sensor array. These operating parameters include:

[0055] Coke oven gas flow rate V g (Unit: m) 3 / h), which is detected using a gas pipeline flow meter;

[0056] The suction force 'a' (in Pa) of the flue gas duct is detected using a flue gas duct pressure sensor;

[0057] The oxygen content (O2) in the flue gas from each flue (in %) was measured using a flue gas analyzer.

[0058] Actual total flue gas flow rate V f (Unit: Nm) 3 / h), detected using an outlet flow meter;

[0059] The coke oven temperature T (in °C) was measured using an infrared thermometer.

[0060] NO x Emission concentration (unit: mg / Nm³) 3 The detection is carried out using an online monitoring instrument installed at the desulfurization and denitrification inlet.

[0061] In step S2 above, the feedforward target refeed amount is obtained through feedforward calculation. The core of feedforward adjustment is to predict the operating conditions by calculating the flue gas flow rate (theoretical flue gas volume) and set the refeed amount benchmark in advance. Specifically:

[0062] The theoretical total flue gas volume is calculated based on coke oven gas flow rate and flue gas suction.

[0063] Multiply the theoretical total flue gas volume by the preset target recycle ratio to obtain the feedforward target recycle amount.

[0064] Calculate the flue gas flow rate (theoretical total flue gas volume) V fl Based on the material conservation law of coke oven gas combustion, the formula for flue gas volume is derived, and combined with the correlation between damper suction and air volume, the theoretical total flue gas volume V is calculated. fl Calculated using the following formula:

[0065] ;

[0066] Among them, V g V represents the coke oven gas flow rate, a represents the flue gas suction force, 0.66 represents the net contribution coefficient on the gas side (calculated based on the material conservation of the combustion reaction of coke oven gas components (methane, hydrogen, etc.), and 17162 and -118386 are the industrial fitting parameters of air volume and flue gas suction force when the damper opening is fixed. fl This refers to the "calculated flue gas flow rate," which reflects the theoretical total amount of flue gas under operating conditions.

[0067] In step S2 above, the target blending ratio is dynamically adjusted according to the coke oven operating conditions; when the coke oven temperature T exceeds the preset threshold, the target blending ratio is increased.

[0068] Set the target repurchase ratio k set Based on experimentally verified optimal operating conditions, the default value is k. set =18%; When coking time is adjusted or furnace temperature T>1260℃, k is dynamically adjusted. set ;

[0069] Calculate the feedforward target return amount V hp :

[0070] ;

[0071] Among them, V fl To calculate the flow rate of flue gas, V g k is the coke oven gas flow rate. set denoted as the target remix ratio, 'a' as the suction force of the flue gas, 0.66 as the net contribution coefficient of the gas side (calculated based on the material conservation of the combustion reaction of coke oven gas components (methane, hydrogen, etc.), and 17162 and -118386 as the industrial fitting parameters of air volume and flue gas suction force when the damper opening is fixed.

[0072] Furthermore, the preset threshold is 1280℃. When the coke oven temperature T exceeds 1280℃, k set Adjusted to 20%, NO x The emission reduction rate can be increased by an additional 3% to 5%, strengthening NO x Inhibition effect.

[0073] In step S3 above, the core of feedback adjustment is to correct the feedforward value by adjusting the deviation of actual operating parameters, thereby eliminating deviations caused by equipment errors and operating condition fluctuations. The feedback correction amount is obtained through feedback correction calculation, specifically as follows:

[0074] Calculate the deviation of oxygen content in flue gas, ΔO2. Where O2 is the measured oxygen content in the flue gas, and O 2，s The target oxygen content in the flue gas; the target oxygen content in the flue gas O 2，s =4~6% (corresponding to the optimal recombinant ratio of 18% for combustion conditions, balancing combustion completeness and NO) x inhibition);

[0075] When the oxygen content deviation ΔO2 in the flue gas is positive, it corresponds to the oxygen concentration in the flue gas being higher than the set value, and the flue gas recirculation rate is increased accordingly. When the oxygen content deviation ΔO2 in the flue gas is negative, it corresponds to the oxygen concentration in the flue gas being lower than the set value, and the flue gas recirculation rate is decreased accordingly.

[0076] Calculate the total flow deviation ΔV f , V f ΔV represents the actual total flue gas flow rate, and V represents the theoretical total flue gas flow rate. fThe allowable deviation between the calculated flow rate and the actual total flow rate of flue gas is determined based on the reasonable range of equipment measurement errors and operating condition fluctuations in industrial experiments;

[0077] When the oxygen content of the flue gas deviates by ΔV f When the value is positive, it corresponds to an actual total flue gas flow rate higher than the theoretical total flue gas flow rate. In this case, the controlled flue gas recirculation rate increases accordingly; the flue gas oxygen content deviation ΔV f When the value is negative, it corresponds to the actual total flue gas flow rate being lower than the theoretical total flue gas flow rate. In this case, the control flue gas recirculation amount is reduced accordingly.

[0078] The control algorithm is used to perform a fusion calculation on the deviation of flue gas oxygen content and total flow rate, and outputs a feedback correction quantity V. hf .

[0079] Furthermore, the control algorithm is a proportional-integral-derivative PID algorithm, employing a dual-input single-output PID algorithm to control ΔO2 and ΔV. f Weighted fusion is performed to obtain the feedback correction amount V. hf Feedback correction amount V hf Calculated using the following formula:

[0080]

[0081] Where, ΔV f The total flow rate deviation is represented by ΔO2, the flue gas oxygen content deviation is represented by ω1 and ω2, and K is the weighting coefficient. p K i K d Here are the PID parameters, and K1 is the proportional coefficient.

[0082] In step S4 above, the flue gas recirculation equipment is a variable frequency fan. The final recirculation amount V is obtained by fusing the feedforward target recirculation amount with the feedback correction amount. h =V hq +V hf via V h Generate adjustment signals to control the frequency of the flue gas return fan, thereby achieving precise control of the return volume.

[0083] Secondly, the present invention also provides a feedforward-feedback coordinated control system for coke oven flue gas recirculation and distribution to implement the above method, comprising:

[0084] The data acquisition module is used to collect coke oven operating parameters in real time. The operating parameters include at least coke oven gas flow rate, flue gas suction, flue gas oxygen content and actual total flue gas flow rate.

[0085] The feedforward calculation module is used to calculate the target feedforward recirculation amount based on the coke oven gas flow rate and the suction of the flue gas duct;

[0086] The feedback correction module is used to calculate the feedback correction amount based on the deviation between the oxygen content of flue gas and the target oxygen content of flue gas, and the deviation between the actual total flue gas flow rate and the theoretical total flue gas flow rate.

[0087] The fusion control module is used to fuse the feedforward target re-fit amount and the feedback correction amount to obtain the final re-fit amount and generate a control signal; and

[0088] The execution module is used to adjust the flue gas recirculation amount according to the control signal.

[0089] In this invention, the data acquisition module includes a gas flow meter, a flue gas pressure sensor, a flue gas oxygen analyzer, a total flue gas flow sensor, a return flow sensor, an infrared thermometer, and a NO meter. x Online monitoring instrument; gas flow meter used to collect coke oven gas flow rate V g The flue gas pressure sensor is used to collect the flue gas suction force 'a', the flue gas oxygen content analyzer is used to collect the flue gas oxygen content 'O2', and the flue gas total flow sensor is used to collect the actual flue gas total flow 'V'. f Infrared thermometers are used to collect coke oven temperatures (T and NO). x Online monitoring instruments are used to collect NO. x Emission concentration.

[0090] In this invention, the feedforward calculation module dynamically adjusts the target recycle ratio based on the coke oven temperature. The feedforward calculation module has a built-in theoretical total flue gas calculation model and a target recycle ratio setting value.

[0091] The feedforward calculation module is equipped with a flue gas volume calculation model and a target recirculation ratio setting unit, used to receive the coke oven gas flow rate V. g With the suction force 'a' of the flue gas duct, and the theoretical total output of flue gas 'V', fl and feedforward target return amount V hq .

[0092] In this invention, the feedback correction module has a built-in PID control algorithm to handle deviations in flue gas oxygen content and total flow rate.

[0093] The feedback correction module is equipped with a PID control algorithm unit, which receives the oxygen content (O2) in the flue gas and the actual total flue gas flow rate (V). f The deviation from their respective set values ​​is calculated, and a feedback correction amount V is output. hf ;

[0094] In this invention, the fusion control module is used to receive the feedforward target relocation amount V. hq With feedback correction amount V hf The final re-allocation amount V is calculated. h And generate corresponding adjustment signals.

[0095] In this invention, the execution module is a variable frequency fan, which is used to receive the adjustment signal and control the amount of flue gas recirculation by adjusting its operating frequency.

[0096] This invention achieves precise and dynamic regulation of coke oven flue gas recirculation through feedforward-feedback coordinated control, effectively solving problems such as poor recirculation ratio adaptability, control lag, and efficiency imbalance in existing technologies, thus providing a solution for coke oven NO2 production. x Emission reduction and thermal optimization provide reliable technical solutions with broad prospects for industrial applications.

[0097] Example

[0098] This embodiment uses a 7m top-loading coke oven of a coking company as the controlled object, and the system configuration is as follows:

[0099] The data acquisition module includes a gas flow meter, a flue gas pressure sensor, a flue gas oxygen content analyzer, a total flue gas flow sensor, and a return flow sensor.

[0100] The control parameter is set as follows: target reprocessing ratio k set = 18%, target flue gas oxygen content O 2,s = 6%, weighting coefficients ω1 = 0.6, ω2 = 0.4, PID parameter K p = 1.1, K i = 0.1, K d = 0.2, proportionality coefficient K1 = 110;

[0101] The execution module is a variable frequency fan with a frequency adjustment range of 0–50 Hz, corresponding to a recirculation quantity adjustment range of 0–7.4 × 10⁻⁶. 4 Nm 3 / h.

[0102] The parameters obtained in real time during the data acquisition process are as follows:

[0103] Coke oven gas flow rate V g = 16500 m³ / h, flue gas suction a = 170 Pa, flue gas oxygen content O2 = 6.1%, actual total flue gas flow rate V f = 112000 Nm³ / h, coke oven temperature T = 1260 ℃, NO x The emission concentration was 450 mg / Nm 3 .

[0104] The feedforward calculation steps include:

[0105] V g Substitute 'a' into the flue gas volume formula Calculate the theoretical total flue gas volume V fl =116269 Nm 3 / h;

[0106] Set the target repurchase ratio k set = 18%, calculate the feedforward target relocation amount V hq = V fl ×k set = 20928.42 Nm 3 / h.

[0107] The feedback correction steps include:

[0108] The oxygen content deviation ΔO2 is calculated to be 0.1%;

[0109] V f -V fl =-4269 Nm 3 / h, calculate the total flow deviation ΔV fl =-3.8%, which is within the allowable deviation range of ±5%;

[0110] Substitute into the PID control algorithm and calculate the feedback correction quantity V. hf ≈-182 Nm 3 / h.

[0111] The final adjustment steps are as follows:

[0112] Calculate the final remix quantity V h = V hq + V hf = 20746.4 Nm 3 / h;

[0113] Based on the fan performance parameters in the execution module, a frequency adjustment signal corresponding to 14 Hz is generated to control the operation of the return fan.

[0114] Operating condition monitoring results show that:

[0115] After the system stabilizes, the oxygen content (O2) in the flue gas is 5.0%, and the actual total flue gas flow rate is V. f 113500 Nm 3 / h, the actual remixing ratio is 18.3%, NO x The emission concentration was 345 mg / Nm³, and all parameters met the requirements of the optimal operating condition.

[0116] Under sudden changes in operating conditions, when the coke oven gas flow rate rises to V g = 17500 m 3 / h, with a flue gas suction force a = 175Pa and an oxygen content (O2) of 5.5% in the flue gas:

[0117] The theoretical total flue gas volume V is calculated using feedforward calculation. fl = 120195.92 Nm 3 / h, feedforward target return quantity Vh q =21635.27 Nm 3 / h;

[0118] Since the oxygen content deviation ΔO2 is zero, the feedback correction amount Vh f The final return quantity is zero, Vh = Vh q = 21635.27 Nm 3 / h corresponds to a fan frequency of 15 Hz.

[0119] Post-stabilization monitoring showed that the actual recovery rate was 18.2%, NO x The emission concentration was 350 mg / Nm 3 The system did not experience combustion deterioration due to sudden changes in operating conditions.

[0120] The present invention has been described above by way of example. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A feedforward-feedback coordinated control method for coke oven flue gas recirculation, characterized in that, Includes the following steps: Real-time acquisition of coke oven operating parameters, including at least coke oven gas flow rate and flue gas suction; Based on the coke oven gas flow rate and the flue gas suction, the feedforward target recycle amount is obtained through feedforward calculation. Real-time collection of flue gas oxygen content and actual total flue gas flow rate; based on the deviation between the flue gas oxygen content and the target flue gas oxygen content, and the deviation between the actual total flue gas flow rate and the theoretical total flue gas flow rate, the feedback correction amount is calculated through feedback correction. The feedforward target reprocessing amount and the feedback correction amount are fused to obtain the final reprocessing amount, and the flue gas reprocessing equipment is controlled according to the final reprocessing amount.

2. The method according to claim 1, characterized in that, The feedforward target allocation amount is obtained through feedforward calculation, specifically as follows: The theoretical total flue gas volume is calculated based on the coke oven gas flow rate and the suction force of the flue gas duct. The feedforward target recycle amount is obtained by multiplying the theoretical total flue gas volume by the preset target recycle ratio.

3. The method according to claim 2, characterized in that, The theoretical total flue gas volume V fl Calculated using the following formula: Where Vg is the coke oven gas flow rate, a is the flue gas suction, and 0.66, 17162, and -118386 are coefficients determined based on the coke oven gas composition and combustion characteristics.

4. The method according to claim 2 or 3, characterized in that, The target blending ratio is dynamically adjusted according to the coke oven operating conditions; when the coke oven temperature exceeds a preset threshold, the target blending ratio is increased.

5. The method according to any one of claims 1 to 4, characterized in that, The feedback correction amount is calculated through feedback correction, specifically as follows: Calculate the deviation of oxygen content in flue gas, ΔO2. Where O2 is the measured oxygen content in the flue gas, and O 2，s The target is the oxygen content in the flue gas; Calculate the total flow deviation ΔV f , V f V represents the actual total flue gas flow rate, and V represents the theoretical total flue gas flow rate. The control algorithm is used to perform a fusion calculation on the deviation of the flue gas oxygen content and the deviation of the total flow rate, and the feedback correction amount is output.

6. The method according to claim 5, characterized in that, The control algorithm is a proportional-integral-derivative PID algorithm, and the feedback correction quantity V hf Calculated using the following formula: ΔV f The total flow rate deviation is represented by ΔO2, the flue gas oxygen content deviation is represented by ω1 and ω2, and K is the weighting coefficient. p K i K d Here are the PID parameters, and K1 is the proportional coefficient.

7. A feedforward-feedback coordinated control system for coke oven flue gas recirculation and distribution to implement the method of any one of claims 1-6, characterized in that, include: The data acquisition module is used to collect coke oven operating parameters in real time. The operating parameters include at least coke oven gas flow rate, flue gas suction, flue gas oxygen content, and actual total flue gas flow rate. The feedforward calculation module is used to calculate the feedforward target recirculation amount based on the coke oven gas flow rate and the flue gas suction. The feedback correction module is used to calculate the feedback correction amount based on the deviation between the oxygen content of the flue gas and the target oxygen content of the flue gas, and the deviation between the actual total flue gas flow rate and the theoretical total flue gas flow rate. The fusion control module is used to fuse the feedforward target re-allocation amount with the feedback correction amount to obtain the final re-allocation amount and generate a control signal; An execution module is used to adjust the flue gas recirculation amount according to the control signal.

8. The system according to claim 7, characterized in that, The data acquisition module includes a gas flow meter, a flue gas pressure sensor, a flue gas oxygen analyzer, a total flue gas flow sensor, a return flow sensor, an infrared thermometer, and a NO meter. x Online monitoring instrument.

9. The system according to claim 7, characterized in that, The feedforward calculation module has a built-in theoretical total flue gas calculation model and a target remix ratio setting value; The feedback correction module has a built-in PID control algorithm to handle the deviation in flue gas oxygen content and the deviation in total flow rate.

10. The system according to claim 7, characterized in that, The execution module is a variable frequency fan, which controls the amount of flue gas recirculation by adjusting the operating frequency.

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